Tennessee-Tombigbee Waterway Water Quality Study
US-EPA, Region 4, SESD, Athens, Georgia
[ Full Report ]
In response to a request from the Alabama Department of Environmental Management (ADEM) and the Mississippi Department of Environmental Quality (MDEQ) through the United States Environmental Protection Agency (EPA), Region 4, Water Management Division (WMD), the Science and Ecosystem Support Division (SESD), Ecological Assessment Branch (EAB) conducted a comprehensive water quality investigation along approximately 35 miles of the Tennessee-Tombigbee Waterway near Columbus, Mississippi. The study was designed to provide a set of water quality and hydraulic data associated with a defined reach of the Tennessee-Tombigbee (Tenn-Tom) Waterway from just above the Columbus/Stennis Pool in Mississippi to just downstream of the Bevill Lock and Dam in Alabama. The data collected during this study was intended to provide insight with respect to: 1) Clean Water Act (CWA) §§ 303 (d)/305 (b) assessments of organic enrichment/dissolved oxygen within the study reach; 2) the water quality and hydraulic characteristics of the system during low flow conditions; and 3) appropriate approaches for representing the system with a water quality model. General observations about the Tenn-Tom Waterway based on the data gathered during this study follow:
1. The study was conducted during critical conditions of low flow and high temperature. Average flow during the study was 1, 840 cubic feet per second (cfs) and the average water temperature was 31°C.
2. The dissolved oxygen concentrations (DO) measured at the majority of the stations sampled during the study were greater than 5.0 mg/l. However, there were several observed DO concentrations less than 5.0 mg/l measured at the 5 foot depth within the State of Alabama.
3. Mild dissolved oxygen stratification existed throughout the system. The trend was more pronounced down stream of station TT324.4.
4. Data collected during this study is sufficient to enhance the existing QUAL2E model or assist with the construction of a dynamic model.
5. The emerging issue of invasive plant species proliferating within the system should be considered. According to the U.S. Army Corp of Engineers, navigation has been impeded due to their excessive growth (personal communication with Allan Brewer). The U.S. Army Corp of Engineers has utilized aerial and boat spraying of herbicides to control the plant growth. The long term affects of the plant growth and subsequent spraying upon water quality within the system are unknown.
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| Final Report
Water Quality Study
|66 pages||819 KiloBytes||Report|
|531 pages||10.2 MegaBytes||Appendices|